A targetable MYBL2-ATAD2 axis governs cell proliferation in ovarian cancer.

The chromatin-modifying enzyme ATAD2 confers oncogenic competence and proliferative advantage in malignances. We previously identified ATAD2 as a marker and driver of cell proliferation in ovarian cancer (OC); however, the mechanisms whereby ATAD2 is regulated and involved in cell proliferation are still unclear. Here, we disclose that ATAD2 displays a classical G2/M gene signature, functioning to facilitate mitotic progression. ATAD2 ablation caused mitotic arrest and decreased the ability of OC cells to pass through nocodazole-arrested mitosis. ChIP-seq data analyses demonstrated that DREAM and MYBL2-MuvB (MMB), two switchable MuvB-based complexes, bind the CHR elements in the ATAD2 promoter, representing a typical feature and principle mechanism of the periodic regulation of G2/M genes. As a downstream target of MYBL2, ATAD2 deletion significantly impaired MYBL2-driven cell proliferation. Intriguingly, ATAD2 silencing also fed back to destabilize the MYBL2 protein. The significant coexpression of MYBL2 and ATAD2 at both the bulk tissue and single-cell levels highlights the existence of the MYBL2-ATAD2 signaling in OC patients. This signaling is activated during tumorigenesis and correlated with TP53 mutation, and its hyperactivation was found especially in high-grade serous and drug-resistant OCs. Disrupting this signaling by CRISPR/Cas9-mediated ATAD2 ablation inhibited the in vivo growth of OC in a subcutaneous tumor xenograft mouse model, while pharmacologically targeting this signaling with an ATAD2 inhibitor demonstrated high therapeutic efficacy in both drug-sensitive and drug-resistant OC cells. Collectively, we identified a novel MYBL2-ATAD2 proliferative signaling axis and highlighted its potential application in developing new therapeutic strategies, especially for high-grade serous and drug-resistant OCs.

[Effect of aspirin on function of human umbilical cord blood-derived late endothelial progenitor cells].

This study was aimed to investigate whether aspirin has effect on function of late endothelial progenitor cells (EPC). Cord blood CD34(+) cells were purified using the ficoll density gradient centrifugation and human CD34 positive selection kit, then the cells were inoculated on fibronectin-coated culture plate. After culture for 2 weeks, adherent cells were identified as EPC by flow cytometry, immunofluorescence, RT-PCR, uptake of Dil-Ac-LDL and matrigel tube formation assay. EPC were treated with different concentrations of aspirin (0.1, 1, 10, 100, 1 000, 10 000 µmol/L) for 24 h, then the proliferation, adhesion and migration ability of these cells were analyzed by CCK-8 assay and transwell methods. The results indicated that the low concentrations of aspirin (0.1 and 1 000 µmol/L) promoted late EPC adhesive and migratory capacity, but no obvious effect on proliferation of late EPC were observed. On the other hand, the high concentrations of aspirin (10 000 µmol/L) inhibited proliferation and migratory capacity of EPC, but had no obvious effect on adhesive ability of EPC. It is concluded that low concentration of aspirin promotes migration and adhesion of late EPC, while the high concentration of aspirin decreases EPC proliferation and migratory capacity of EPC.